Coating for smoking pipes and the like



' Patented. May 3, 1938 UNITED *STATES COATING FOR SMOKING PIPES AND THE Andrew Buschman, Garden City, N. Y.

No Drawing. Application November 10, 1937,-

Serial No. 173,842

3 Claims. (on. 13142) This invention relates to'the coating of smoking pipes, and in particular to the coating which is applied to the wooden bowl of the pipe.

In themanufactured smoking pipesit is 5 common practice touse briar wood orcother suit able material, which is generally of such a texture as to require a finish to make the surface smooth and hard.

There are several "important reactions which take place when a smoking pipe is used, which makes it'necessary to develop a special coating or finish which will withstand these peculiar developments.

The old practice was to cut the briar wood to the shape of the bowl and shank of the pipe, whereupon it was sanded to a smooth surface,

and then coated with shellac which was subsequently polishedafter hardening. The general problem is to provide a finish which will stand up in use, and retain the pipe in its original polished and perfect condition.

When the pipe is used, thebowl becomes hea-ted, and this'tends to spoil any so-called thermo plastic material which has been used as a finish. 5 It not only breaks down the material which makes it soft, but it tends to cloud the surface and change the entire appearance of the pipe.

Another difliculty arises from the fact that the burning'of the tobacco in the bowl of the pipe tends to expand the bowl, which is liable to crack the finish if it is not of 1 a somewhat flexible nature. The heating of the bowl is, also liable to produce blistering if the.coating is not of a proper nature. Aside from these difficulties with the finish which arise mainly from the heat produced in the pipe, there is also a serious problem presented, due to the holding of the pipe in the hand of the smoker. The heated pipe, with the coating likewise raised in temperature, is subjected to the attack of acid from the hand of the smoker, which, unless the coating is made from proper materials, will break down thecoat-- ing, entirely destroying its luster, and in fact, will remove it entirely in time. It seems that the fingers of the smoker liberate considerable amounts of-acid while holding a heated pipe. For this reason the applicant has developed a special coating which is so compounded as to meet all of the conditions as previously set forth.

0 To'begin with, the applicant finds that the most suitable material to'form the body of the coating is a compound based upon the use of urea resin and nitrocellulose, combined in such a way and with such solvents as to produce an effective -coating which is both heat and acid ness of the coating; in other words, if the coating is applied toothickly, then the pores in the proof. Attempts have been made to use nitrocellulose compounds, but compounds'made with this alone are entirely unsuitable, as they are very susceptible to the attack of acid. Furthermore, compounds-using nitrocellulosecombined 5 with ethyl cellulose are subjected to the same diiflc'ulty, and furthermore, must be applied with great care in order to avoid blistering. Both nitrocellulose and ethyl cellulose are thegrmo plastics which are seriously eifected by even the 10 low temperatures of slow smoking, and if the pipe is smoked excessively or to such an extent as to develop considerable heat, they immediately cloud or blister.

The applicant has therefore. used urea resin which in itself is acid free and is highly acid resistant, and has'used only suificient nitrocellulose to give the coating proper expansive properties.- In order to apply this body to thesurface of the wood in a proper and uniform manner, a number of solvents have been used, and in such proportions as have been found to, properly dissolve and convey the body materials.

.The applicant has found that the smoking pipe should have a certain amount of porosity even through the coating after applied, in order that it may breathe away the moisture which is generated-when the tobacco is burned. This is obtained and provided entirely by the thin-' wood are entirely sealed, and this breathing" action is entirely prevented. This is the case no matter what the coating may be. For this reason it is desirable. to apply the coating as thinly aspossible, and this requires that .the coating have a high luster and be proof against the various elements mentioned, even when it has little thickness. It is therefore necessary to use some such body material as urearesin which is acid free and acid resistant.

Urea resin, when compounded in the applicants formula, has a characteristic which makes it particularly adaptable to this kind of application, in that when it is heated, it turns over and becomes insoluble in its own solvents. This is peculiar to the applicant's coating, and is not the case with the usual nitrocellulose ethyl cellulose compounds. The nitrocellulose ethyl cellulose compounds are thermo plastic materials which will dry and leave a smooth lustrous finish, but they do not "turn over during the heating process,. and do not become insoluble in their own solvents, and they are not acid resistant at any time. I I

The applicant has found that the best compound to produce the results necessary is, composed of the following:

It will be noted that the nitrocellulose and the urea resin constitute the body of the coating, and the rest of the formula constitutes the usual solvents used with such compounds and the properties of each are commonly known to chemists familiar with the manufacture of lacquers. The percentages of each of the solvents used have been worked out according to the usual practice in the mixing of coatings in order to produce a properly balanced finish.

After the coating has been compounded approximately in accordance with the formula as outlined above, it may be applied to a pipe by either spraying or dipping, or any of the methods used in industrial finishing, whereupon it is permitted to dry. If a very high finish is required, it is the usual practice to polish the coating by bufiing. The usual commercial method of finishing wood products, wherein the wood is preheated in an oven to drive out air and moisture, and is then sprayed with a coating and then replaced in the oven for baking, is not practical for the finishing of pipes, because the heat required to bake the coating tends to distort the pipe stem to such an extent that the bit does not fit after this heating. For this reason, the finish is permitted to merely air-dry, and the manufacturers of the pipes can then be assured that their dimensions will not be disturbed. The usual finishes, therefore, are not baked, and depend entirely upon the heating of the pipe when being smoked for a temperature suiiicientto set the finish coating. The coatings in use today using nitrocellulose andethyl cellulose, are not affected to advantage by this heating of the pipe when in service, but tend to give way to the heat by becoming soft or blistering. The applicants coating has all of the advantages of the other coatings, and in addition thereto, has the property of turning over during the heating process, and becoming as a result thereof acid resistant and insoluble in its own solvents.

Having described the invention, what is claimed as new and desired to secure by Letters Patent is:

1. A combination of a smoking article having a chamber within which smoking material is to be burned, and an exterior coating therefor; said coating consisting of a compound of nitro eellulose and urea resin, which when heated turns over and becomes acid resistant and insoluble in its own solvents, said heating being effected when the smoking material is burned therein.

2. The method of making a smoking pipe comprising the steps of treating the exterior thereof with a compound consisting of Parts by weight applying smoking material in the interior thereof, and burning said material, thereby heating the exterior surface and "causing a turning over of the compound, whereby a permanent finish is obtained.

3. The method of making a smoking pipe, comprising the steps of treating the exterior thereof with a compound of nitrocellulose and urea resin, applying smoking material in the interior thereof, and burning the said material, thereby heating the exterior surface and causing a turnning over of the compound, whereby a permanent finish is obtained.

ANDREW BUSCHMAN. 

